This invention relates to a method of producing microbial cells utilizing methane as the main carbon source.
Methane is one of the most inexpensive carbon sources for microbial growth. It is known that there are many microorganisms capable of growing on a culture medium in the presence of methane as the principle carbon source. However the growth of the most known strains is quite low and unsatisfactory. With mixed cultures, superior growth strains are known. But when the strains are isolated, this superior property of the original strain mixture is somehow lost (Applied Microbiology, 15, 1473-1478 (1967) and 21, 511-515 (1971)). With pure cultures, superior strains, capable of good growth, are not known. Since it is difficult to maintain stable mixed cultures during a large number of cycles, the industrial production of single cell protein from methane is a problem.